Measuring overload effects during fatigue crack growth in bainitic steel by synchrotron X-ray diffraction
(2015) In International Journal of Fatigue 71. p.11-16- Abstract
- In this work we present the results of in situ synchrotron X-ray diffraction measurements of fatigue crack-tip strain fields following a 100% overload (OL) under plane strain conditions. The study is made on a bainitic steel with a high toughness and fine microstructure. This allowed a very high (60 mu m) spatial resolution to be achieved so that fine-scale changes occurring around the crack-tip were captured along the crack plane at the mid-thickness of the specimen. We have followed the crack as it grew through the plastic/residually stressed zone associated with the OL crack location. We observed two effects; one when the enhanced plastic zone is ahead of the crack and one after it has been passed. Regarding the former it was found that... (More)
- In this work we present the results of in situ synchrotron X-ray diffraction measurements of fatigue crack-tip strain fields following a 100% overload (OL) under plane strain conditions. The study is made on a bainitic steel with a high toughness and fine microstructure. This allowed a very high (60 mu m) spatial resolution to be achieved so that fine-scale changes occurring around the crack-tip were captured along the crack plane at the mid-thickness of the specimen. We have followed the crack as it grew through the plastic/residually stressed zone associated with the OL crack location. We observed two effects; one when the enhanced plastic zone is ahead of the crack and one after it has been passed. Regarding the former it was found that the compressive stress at the crack-tip initially falls sharply, presumably due to the increased plastic stretch caused by the OL. This is associated with a concomitant fall in peak tensile stress at K-max, the elastic excursion between K-min and K-max remaining essentially unchanged from before OL. Subsequently discontinuous closure as seen previously for plane stress caused by crack face contact at the OL location limits the elastic strain range experienced by the crack tip and thereby retards crack growth. (C) 2014 Elsevier Ltd. All rights reserved. (Less)
Please use this url to cite or link to this publication:
https://lup.lub.lu.se/record/5297304
- author
- Lopez-Crespo, P. ; Steuwer, Axel LU ; Buslaps, T. ; Tai, Y. H. ; Lopez-Moreno, A. ; Yates, J. R. and Withers, P. J.
- organization
- publishing date
- 2015
- type
- Contribution to journal
- publication status
- published
- subject
- keywords
- Overload effect, Fatigue crack closure, Residual stress, X-Ray, diffraction
- in
- International Journal of Fatigue
- volume
- 71
- pages
- 11 - 16
- publisher
- Elsevier
- external identifiers
-
- wos:000350599100003
- scopus:84915805286
- ISSN
- 1879-3452
- DOI
- 10.1016/j.ijfatigue.2014.03.015
- language
- English
- LU publication?
- yes
- id
- 547c958b-997e-479b-9cbe-047237e38f7b (old id 5297304)
- date added to LUP
- 2016-04-01 10:40:23
- date last changed
- 2022-04-12 08:31:20
@article{547c958b-997e-479b-9cbe-047237e38f7b,
abstract = {{In this work we present the results of in situ synchrotron X-ray diffraction measurements of fatigue crack-tip strain fields following a 100% overload (OL) under plane strain conditions. The study is made on a bainitic steel with a high toughness and fine microstructure. This allowed a very high (60 mu m) spatial resolution to be achieved so that fine-scale changes occurring around the crack-tip were captured along the crack plane at the mid-thickness of the specimen. We have followed the crack as it grew through the plastic/residually stressed zone associated with the OL crack location. We observed two effects; one when the enhanced plastic zone is ahead of the crack and one after it has been passed. Regarding the former it was found that the compressive stress at the crack-tip initially falls sharply, presumably due to the increased plastic stretch caused by the OL. This is associated with a concomitant fall in peak tensile stress at K-max, the elastic excursion between K-min and K-max remaining essentially unchanged from before OL. Subsequently discontinuous closure as seen previously for plane stress caused by crack face contact at the OL location limits the elastic strain range experienced by the crack tip and thereby retards crack growth. (C) 2014 Elsevier Ltd. All rights reserved.}},
author = {{Lopez-Crespo, P. and Steuwer, Axel and Buslaps, T. and Tai, Y. H. and Lopez-Moreno, A. and Yates, J. R. and Withers, P. J.}},
issn = {{1879-3452}},
keywords = {{Overload effect; Fatigue crack closure; Residual stress; X-Ray; diffraction}},
language = {{eng}},
pages = {{11--16}},
publisher = {{Elsevier}},
series = {{International Journal of Fatigue}},
title = {{Measuring overload effects during fatigue crack growth in bainitic steel by synchrotron X-ray diffraction}},
url = {{http://dx.doi.org/10.1016/j.ijfatigue.2014.03.015}},
doi = {{10.1016/j.ijfatigue.2014.03.015}},
volume = {{71}},
year = {{2015}},
}